Now, I think I know what this one is! It is a Pallme-Koenig perfume bottle in what is known as frit decor, with veining, or threading - more examples can be found at kralik-glass.com.
The collar and stopper top are English sterling silver - hallmarked for Birmingham, 1910. That probably explains why the collar shape feels, to me at least, to be leaning more towards the deco than the nouveau period.
The colour is a beautiful deep honey or caramel and the iridescence is rich in purples and pinks. Very hard to capture in photos, but very tactile.
This one came from manddmoir - so thank you, Mike and Debbie!